New York State Assembly Speaker Sheldon Silver turned himself into federal authorities Thursday morning on charges of corruption and bribery. Federal prosecutors say that Silver, who served as the Assembly Speaker for over two decades, abused his political office by accepting bribes and kickbacks worth millions of dollars.

In a five-count criminal complaint outlining the charges, the Manhattan Democrat is accused of "using the power and influence of his official position to obtain for himself millions of dollars of bribes and kickbacks masked as legitimate income," reports the New York Times.

"There is probable cause to believe Silver obtained about $4 million in payments characterized as attorney referral fees solely through the corrupt use of his official position," authorities said in the complaint.

A federal corruption probe launched against the politician in 2013 reportedly found that for the last decade he underhandedly accepted payments from a small law firm called Goldberg & Iryami that specializes in seeking reductions of New York City real estate taxes. FBI agents and prosecutors with U.S. Attorney Preet Bharara's office also said that Silver did essentially no work for the payments, nor did he officially disclose the payments.

Silver's lawyers, however, released a statement calling the accusations "meritless."

"We're disappointed that the prosecutors have chosen to proceed with these meritless criminal charges. That said, Mr. Silver looks forward to responding to them -- in court -- and ultimately his full exoneration," said Joel Cohen and Steven Molo.

In response, Democrat State Senator Brad Hoylman blasted the Speaker on Twitter on Thursday, demanding his resignation.

"Speaker Silver should resign for the good of the people of New York," he said.

Assemblyman Mickey Kearns also called for Silver to step down.

"Secret settlements, sex scandals and now criminal allegations. All of the above should disqualify Silver from keeping leadership position," he tweeted.